With recent improvements in semiconductor technology, recording media such as SD memory cards have shrunk in size and grown in capacity. As a result, recording media are increasingly equipped in portable terminals such as mobile phones and PDAs and put to use. In other words, portable terminals that are equipped with recording media which store content such as image and music data, and that realize an additional function of content reproduction as well as their original function of communication and the like, are becoming widely available.
To execute such an additional function in a portable terminal equipped with a recording medium, the recording medium needs to be operated. This requires a large amount of power to be supplied from a battery in the portable terminal to the recording medium.
However, when the remaining capacity of the battery is low, if the execution of the additional function is continued, the battery in the portable terminal may become exhausted. When this happens, the portable terminal cannot perform its original function.